pH-sensitive Properties Research Articles

Metal Polyphenol Nanoparticle-Based Chemo/Ferroptosis Synergistic Therapy for the Treatment of Oral Squamous Cell Carcinoma.

Despite the use of surgical resection and chemotherapy in the clinical treatment of oral squamous cell carcinoma (OSCC), the 5-year survival rates of advanced patients are low. Therefore, more efficient strategies are urgently needed. Herein, a chemo/ferroptosis synergistic therapeutic system-DMEFe nanoparticles (NPs) is established for the treatment of OSCC. To create this system, the chemotherapeutic agent doxorubicin (DOX) was loaded into mesoporous silica nanoparticles and further coated with a pH-sensitive metal polyphenol (iron ion and epigallocatechin gallate). These nanoparticles displayed excellent pH-sensitive drug-control release properties, and the release ratio of DOX at pH 5.5 was twice as high than that at pH 7.4. Additionally, DMEF NPs were effectively taken up by the OSCC cell line SSC-25, which greatly impeded the proliferation of these cells. Notably, these nanoparticles increased the intracellular level of reactive oxygen species and effectively exhibited cytotoxity effects. The mechanistic results proved that DMEFe NPs regulated the expression of ferroptosis-related genes to induce ferroptosis of SSC-25 cells. Eventually, this chemo/ferroptosis therapeutic system exhibited remarkable antitumor effects and provided a novel strategy for the treatment of OSCC.

Ionic liquid combined with cationic liposome co-delivers microphthalmia-associated transcription factor small interfering RNA to regulate melanogenesis

Suppressing allele-specific genes using small interfering RNAs (siRNAs) can effectively whiten skin by influencing cellular gene and protein expression. Topical delivery of siRNA is a promising alternative to injections for RNA interference. However, the barrier function of the skin hinders the effective penetration of siRNA. Here, we report, a novel approach to achieve the transdermal delivery of effective siRNA doses using a complementary synergistic strategy of an ionic liquid (IL) and cationic liposome (CL). Microphthalmia-associated transcription factor (MITF) siRNA molecules were formed through electrostatic adsorption of the IL and CL to form positively charged nanocomposites, which were named IL-CL/p-siM. IL-CL/p-siM has a particle size of 171.47 nm, ζ-potential of 29.94 mV, high encapsulation rate of 92.11 %, and pH-sensitive release properties. In vitro studies on porcine skin confirmed the additive/synergistic effect of this strategy in enhancing epidermal and dermal penetration. This combination enabled superior transfection efficiency and cell viability while inhibiting melanin synthesis in skin melanocytes by downregulating the expression of genes downstream of MITF, namely tyrosinase-related protein-1, tyrosinase, and tyrosinase-related protein-2, which are associated with the melanocortin 1 receptor. We also conducted clinical studies that demonstrated its potential in treating melasma and its anti-melanotic efficacy. To summarize, IL-CL/p-siM represents a simple, personalized, and scalable platform for effective local delivery of siRNA to treat skin complications.

Preparation and recovery performance of modified cellulase with pH-sensitive separation properties

The efficient utilization of biomass resources holds significant importance for sustainable development in the energy, materials, and chemical industries. Therefore, it has garnered widespread attention. In this study, we have successfully achieved pH-sensitive separation and recycling of cellulase in an aqueous system. Firstly, the cellulase was modified by introducing a polyethylene glycol modifier with an aromatic aldehyde group. This modification altered the conformation of the cellulase and created a homogeneous-like system due to the hydrophilicity of the ethoxyl group in the modifier. As a result, the accessibility of the enzyme to the substrate was improved, which led to an increase in the enzyme activity of 116.12 %. The aromatic aldehyde group in the modifier and the primary amino group in the polyethyleneimine (PEI) formed a dynamic Schiff base covalent bond, which had pH-sensitive properties to ensure the completion of the recycling of the enzyme in the aqueous system. It was found that the molecular weight of PEI affected the recovery properties of the enzyme. Under the condition that the enzymatic activity was not damaged, the recovery rate of enzymatic activity increased as the molecular weight of the PEI increased. Particularly, when the molecular weight of PEI was 1800, the modified cellulase still retained an enzymatic activity recovery rate of 80 % after 5 cycles. This research provides a novel solution to improve the efficient hydrolysis of cellulose and the recovery of cellulase.

PEGylated pH-Responsive Liposomes for Enhancing the Intracellular Uptake and Cytotoxicity of Paclitaxel in MCF-7 Breast Cancer Cells.

This study aimed to develop paclitaxel (PTX)-loaded PEGylated (PEG)-pH-sensitive (SpH) liposomes to enhance drug delivery efficiency and cytotoxicity against MCF-7 breast cancer cells. PTX-loaded PEG-SpH liposomes were prepared using the thin film hydration method. ATR-FTIR compatibility studies revealed no significant interactions among liposome formulation components. TEM images confirmed spherical morphology, stability, and an ideal size range (180-200nm) for improved blood circulation. At pH 5.5, liposomes exhibited increased size and positive zeta potential, indicating pH-sensitive properties due to CHEMS response to the acidic tumor microenvironment. Conversely, at pH 7.4, liposomes showed a slightly larger size (199.25 ± 1.64nm) and a more negative zeta potential (-36.94 ± 0.32mV), suggesting successful PEG-SpH surface modification, enhancing stability, and reducing aggregation. PTX-loaded PEG-SpH liposomes demonstrated high encapsulation efficiency (84.57 ± 0.92% w/w) and drug loading capacity (4.12 ± 0.26% w/w). In-vitro drug release studies revealed accelerated first-order PTX release at pH 5.5 and a controlled zero-order release at pH 7.4. Cellular uptake studies on MCF-7 cells demonstrated enhanced PTX uptake, attributed to mPEG-PCL incorporation prolonging circulation time and CHEMS facilitating PTX release in the tumor microenvironment. Furthermore, PTX-loaded PEG-SpH liposomes exhibited significantly improved cytotoxicity with an IC50 value of 1.107µM after 72-h incubation, approximately 90% lower than plain PTX solution. Stability studies confirmed the robustness of the liposomal formulation under various storage conditions. These findings highlight the potential of PEGylated pH-responsive liposomes as effective nanocarriers for enhancing PTX therapy against breast cancer.

Spatio-temporally controlled all-in-one hydrogel microspheres for ulcerative colitis treatment based on cocktail strategy

Due to the complex pathogenesis of ulcerative colitis (UC), particularly excessive reactive oxygen species (ROS), gut microbiota dysbiosis, and hyperpolarization of M1 macrophages, the cocktail strategy is urgently needed to obtain a sufficient therapeutic outcome. Meanwhile, the accurate lesion location targeting of these combined therapeutic agents is still crucial. Herein, based on NPs-in-MPs approach, a novel integrated “all-in-one” oral delivery system (BMM/MPs), containing the natural gut microbiota regulator berberine, MnO2 nanoenzymes, and cell penetrating peptides-decorated magnolol liposomes to regulate macrophage polarization, was constructed to address these above issues in sequence. BMM/MPs could non-destructively cross the gastrointestinal tract, enduringly detain, and dissociate in the colon site due to the pH-sensitive properties. Conceivably, the released MnO2 nanoenzymes depleted the excess ROS at the colitis location into O2, sequentially promoting the acceleration of hydrogel microspheres rupture and oxidative damage remission. Accordingly, the oral administration of BMM/MPs exhibited remarkably satisfactory therapeutic effects against DSS-induced UC mice, by ameliorating the representative symptoms, scavenging ROS, relieving inflammation, and inhibiting M1 macrophage polarization at colon sites. Meanwhile, the dysbiosis of microbes was effectively regulated by facilitating SCFAs production. This study provides a feasible strategy for administration in the treatment of UC.

Novel avenues for achieving simultaneous high-efficiency oil removal and sterilization: Designing a quaternary ammonium-hydrophobic ternary template copolymer

In treating complex sewage containing microorganisms, flocculation and disinfection typically occur as distinct stages, involving the addition of flocculants and disinfectants separately. To integrate oil removal and disinfection, a novel quaternary ammonium-hydrophobic ternary template polymer, TPAMA-DA, was engineered with capabilities for both flocculation and sterilization functions. Optimal copolymer characteristics were determined through Response Surface Methodology of the preparation parameters for TPAMA-DA. The copolymer prepared was applied to model wastewater, and the results indicate that, in emulsified oil and E. coli single systems, TPAMA-DA achieved removal rates of 95.71 % and 97.19 % for emulsified oil and OD600 (residual OD600 = 0.0239), respectively, showcasing superior oil removal and antibacterial capabilities compared to TPAMA and PAMA. Meanwhile, TPAMA-DA exhibited excellent oil removal efficiency across a broad range of pH environments, contrasting sharply with its pH-sensitive antibacterial properties. Surprisingly, applying TPAMA-DA to the oil-E. coli binary systems, it not only maintained high efficiency in oil removal but also showed certain pH adaptability in antibacterial activity, suggesting TPAMA-DA’s outstanding ability for simultaneous oil removal and antibacterial action in oil-E. coli binary systems. Impressively, SEM and 3D-EEM analyses confirm that TPAMA-DA disrupts the bacterial cell, resulting in the death of E. coli. These findings may pave the way for new avenues in the development of multi-functional, efficient, low-consumption, and environmentally friendly high-performance copolymers with dual capabilities for oil removal and sterilization.

αvβ3 Integrin and Folate-Targeted pH-Sensitive Liposomes with Dual Ligand Modification for Metastatic Breast Cancer Treatment.

The advent of pH-sensitive liposomes (pHLips) has opened new opportunities for the improved and targeted delivery of antitumor drugs as well as gene therapeutics. Comprising fusogenic dioleylphosphatidylethanolamine (DOPE) and cholesteryl hemisuccinate (CHEMS), these nanosystems harness the acidification in the tumor microenvironment and endosomes to deliver drugs effectively. pH-responsive liposomes that are internalized through endocytosis encounter mildly acidic pH in the endosomes and thereafter fuse or destabilize the endosomal membrane, leading to subsequent cargo release into the cytoplasm. The extracellular tumor matrix also presents a slightly acidic environment that can lead to the enhanced drug release and improved targeting capabilities of the nano-delivery system. Recent studies have shown that folic acid (FA) and iRGD-coated nanocarriers, including pH-sensitive liposomes, can preferentially accumulate and deliver drugs to breast tumors that overexpress folate receptors and αvβ3 and αvβ5 integrins. This study focuses on the development and characterization of 5-Fluorouracil (5-FU)-loaded FA and iRGD surface-modified pHLips (FA-iRGD-5-FU-pHLips). The novelty of this research lies in the dual targeting mechanism utilizing FA and iRGD peptides, combined with the pH-sensitive properties of the liposomes, to enhance selective targeting and uptake by cancer cells and effective drug release in the acidic tumor environment. The prepared liposomes were small, with an average diameter of 152 ± 3.27 nm, uniform, and unilamellar, demonstrating efficient 5-FU encapsulation (93.1 ± 2.58%). Despite surface functionalization, the liposomes maintained their pH sensitivity and a neutral zeta potential, which also conferred stability and reduced aggregation. Effective pH responsiveness was demonstrated by the observation of enhanced drug release at pH 5.5 compared to physiological pH 7.4. (84.47% versus 46.41% release at pH 5.5 versus pH 7.4, respectively, in 72 h). The formulations exhibited stability for six months and were stable when subjected to simulated biological settings. Blood compatibility and cytotoxicity studies on MDA-MB-231 and SK-BR3 breast cancer cell lines revealed an enhanced cytotoxicity of the liposomal formulation that was modified with FA and iRGD compared to free 5-FU and minimal hemolysis. Collectively, these findings support the potential of FA and iRGD surface-camouflaged, pH-sensitive liposomes as a promising drug delivery strategy for breast cancer treatment.

Exploring the Therapeutic Potential of 5-Fluorouracil-Loaded Calcium Carbonate Nanoparticles Combined with Natural Compound Thymoquinone for Colon Cancer Treatment.

Given the need for novel and effective therapies for colon cancer, this study aimed to investigate the effects of 5-fluorouracil-loaded calcium carbonate nanoparticles (5FU-CaCO3np) combined with thymoquinone (TQ) against colon cancer. A shaking incubator and a high-speed homogenizer were used to prepare the optimal 5FU-CaCO3np, with characterizations of physicochemical properties, in vitro drug release profile, and biocompatibility. In vitro experiments and molecular docking were employed to evaluate the therapeutic potential of the combination for colon cancer treatment. Study results revealed that 5FU-CaCO3np with a size of approximately 130 nm was synthesized using the high-speed homogenizer. Its favorable biocompatibility, pH sensitivity, and sustained release properties facilitated reduced toxic side effects of 5-FU on NIH3T3 normal cells and enhanced inhibitory effects on CT26 colon cancer cells. The combination of 5FU-CaCO3np (1.875 μM) and TQ (30 μM) showed significantly superior anti-colon cancer effects to 5FU-CaCO3np alone in terms of cell proliferation and migration inhibition, cell apoptosis induction, and spheroid growth suppression in CT26 cells (p < 0.05), with strong interactions between the drugs and targets (E-cadherin, Bcl-2, PCNA, and MMP-2). These results provide evidence for 5FU-CaCO3np as a novel regimen against colon cancer. Combining 5FU-CaCO3np and TQ may offer a new perspective for colon cancer therapy.

Dimerization and liquid-liquid phase separation of the nonrepetitive domains of pyriform spidroin 1 controls the pyriform silk formation

Spiders spin high performance silks with diverse mechanical properties for specific biological functions. Of these spider silk types, pyriform silk stands out as a unique combination of wet glue and dry fibers. Investigation of self-assembly process of spider silk proteins is necessary for elucidating the silk formation mechanism. However, the functions of nonrepetitive domains in the silk formation of pyriform spidroins from liquid proteins to solid fibers are still unclear, making it difficult to achieve efficient biomimetic preparations of pyriform silk with good mechanical properties. In this study, we investigate the roles of the N-linker repeat (NLR) and both terminal domains of pyriform spidroin 1 (PySp1) in the silk formation. We demonstrate for the first time that the PySp1 NLR alone is sufficient to self-assemble into high strength fibers. Moreover, we showed that the ability to promote the pyriform silk formation by the addition of the NLR. We also found that the pH-sensitive dimerization property for N-terminal domain and the liquid-liquid phase separation (LLPS) coupled with acidification triggers the self-assembly mediated by the C-terminal domain. Overall, our results provide new insight into the role of nonrepetitive domains in the pyriform silk formation mechanism and the basis for producing new protein-based materials derived from spider pyriform silk.

CS/PVP Hydrogel-Based Nanocapillary for Monitoring Bacterial Growth and Rapid Antibiotic Susceptibility Testing.

Infection with drug-resistant bacteria poses a significant threat to human health. Judicious use of antibiotics could reduce the likelihood of bacterial resistance, which can be evaluated through antibiotic susceptibility testing (AST). This paper focuses on the application of a needle-like nanocapillary tip filled with chitosan (CS)/polyethylene pyrrolidone (PVP) hydrogel based on its specific pH-sensitive properties. The gel-filled nanocapillary has the potential to be used for electrical pH detection with a sensitivity of 3.06 nA/pH and a linear range from 7.3 to 4.3. Such sensitivity for pH measurement could be extended for monitoring of bacterial (such as Escherichia coli and Streptococcus salivarius) growth because of the relationship between pH and bacterial growth. Bacterial growth curves obtained using the hydrogel-filled nanocapillary showed good agreement with the OD600 method. Moreover, this device could be applied for rapid AST for tetracycline and norfloxacin on E. coli with minimum inhibitory concentrations of 2 and 0.125 μg/mL, respectively. This study expands the application of the hydrogel-based nanocapillary for bacterial research by monitoring changes in pH values.

Targeted H2S-Mediated Gas Therapy with pH-Sensitive Release Property for Myocardial Ischemia-Reperfusion Injury by Platelet Membrane.

Management of myocardial ischemia-reperfusion injury (MIRI) in reperfusion therapy remains a major obstacle in the field of cardiovascular disease, but current available therapies have not yet been achieved in mitigating myocardial injury due to the complex pathological mechanisms of MIRI. Exogenous delivery of hydrogen sulfide (H2S) to the injured myocardium can be an effective strategy for treating MIRI due to the multiple physiologic functions of H2S, including anti-inflammatory, anti-apoptotic, and mitochondrial protective effects. Here, to realize the precise delivery and release of H2S, we proposed the targeted H2S-mediated gas therapy with pH-sensitive release property mediated by platelet membranes (PMs). In this study, a biomimetic functional poly(lactic-co-ethanolic acid) nanoparticle (RAPA/JK-1-PLGA@PM) was fabricated by loading rapamycin (RAPA; mTOR inhibitor) and JK-1 (H2S donor) and then coated with PM. Invitro observations were conducted including pharmaceutical evaluation, H2S release behaviors, hemolysis analysis, serum stability, cellular uptake, cytotoxicity, inhibition of myocardial apoptosis, and anti-inflammation. Invivo examinations were performed including targeting ability, restoration of cardiac function, inhibition of pathological remodeling, and anti-inflammation. RAPA/JK-1-PLGA@PM was successfully prepared with good size distribution and stability. Utilizing the natural infarct-homing ability of PM, RAPA/JK-1-PLGA@PM could be effectively targeted to the damaged myocardium. RAPA/JK-1-PLGA@PM continuously released H2S triggered by inflammatory microenvironment, which could inhibit cardiomyocyte apoptosis, realize the transition of pro-inflammation, and alleviate myocardial injury demonstrated in hypoxia/reoxygenation myocardial cell invitro. Precise delivery and release of H2S attenuated inflammatory response and cardiac damage, promoted cardiac repair, and ameliorated cardiac function proven in MIRI mouse model invivo. This research outlined the novel nanoplatform that combined immunosuppressant agents and H2S donor with the pH-sensitive release property, offering a promising therapeutic for MIRI treatment that leveraged the synergistic effects of gas therapy.

Combining Gut Microbiota Modulation and Enzymatic-Triggered Colonic Delivery by Prebiotic Nanoparticles Improves Mouse Colitis Therapy.

The efficacy of ulcerative colitis (UC) therapy is closely connected to the composition of gut microbiota in the gastrointestinal tract. Prebiotic-based nanoparticles (NPs) provide a more precise approach to alleviate UC via modulating gut microbiota dysbiosis. The present study develops an efficient prebiotic-based colon-targeted drug delivery system (PCDDS) by using prebiotic pectin (Pcn) and chitosan (Csn) polysaccharides as a prebiotic shell, with the anti-inflammatory drug sulfasalazine (SAS) loaded into a poly(lactic-co-glycolic acid) (PLGA) core to construct SAS@PLGA-Csn-Pcn NPs. Then, we examine its characterization, cellular uptake, and invivo therapeutic efficacy. The results of our study indicate that the Pcn/Csn shell confers efficient pH-sensitivity properties. The gut microbiota-secreted pectinase serves as the trigger agent for Pcn/Csn shell degradation, and the resulting Pcn oligosaccharides possess a substantial prebiotic property. Meanwhile, the formed PCDDSs exhibit robust biodistribution and accumulation in the colon tissue, rapid cellular uptake, efficient invivo therapeutic efficacy, and modulation of gut microbiota dysbiosis in a mouse colitis model. Collectively, our synthetic PCDDSs demonstrate a promising and synergistic strategy for UC therapy.

Oral alginate microspheres for the efficient site-specific delivery of epidermal growth factor attenuated murine ulcerative colitis via repairing the mucosal barrier

Ulcerative colitis (UC) is a chronic bowel inflammatory disease affecting the colorectum. Epidermal growth factor (EGF) has been demonstrated to be effective to counteract UC. However, there exists the gastrointestinal challenges such as stomach acid, enzyme and bile salts for oral delivery of EGF. Herein, calcium alginate microsphere was prepared by the microfluidic technique to encapsulate EGF. The morphology of EGF-loaded microsphere (MS-EGF) was spherical and its average particle size was 80 ± 23 μm. The encapsulation efficiency of EGF was reaching to 93.8 % ± 1.6 %. In vitro release experiments showed that MS-EGF presented the good pH-sensitive properties, that was, it could effectively resist the gastric acid and small intestinal fluids, and undergone the rapid dissolution in the artificial colon fluid. In vitro cellular experiments demonstrated that the bioactivity of EGF was well preserved by microsphere. Moreover, in vivo murine colitis model showed that MS-EGF presented the obvious colitis alleviation. Furthermore, the colonic morphology of colitis mice was effectively recovered and the tight junction between the gut epithelium was obviously repaired. In conclusion, calcium alginate microsphere might be a promising vehicle of EGF for UC treatment.

Baicalein loaded liposome with hyaluronic acid and Polyhexamethylene guanidine modification for anti methicillin-resistant Staphylococcus aureus infection

Targeting delivery to the infection site and good affinity of vehicle to the bacterial are two main concerns in therapy of bacterial infection, and on-demand release of drug is another important issue. In this work, a liposome drug delivery system (HA/P/BAI-lip) incorporated with baicalein and modified by PHMG and HA was prepared. Several characterizations were conducted to examine the physical properties of liposome. Then it was applied to treatments of MRSA induced dorsal subcutaneous abscess model and the thigh muscle infected model. The presence of guanidine group in HA/P/BAI-lip rendered the liposome satisfactory bacterial target ability and good pH sensitive properties. The lipase secreted by bacterial could promote the hydrolysis of soybean phosphatidylcholine (SPC) in liposome. The modification of HA in HA/P/BAI-lip could lead the drug system to the exact infected site where CD44 was abundant because of inflammation. The low pH microenvironment characteristic of bacterial infection could induce the swelling of liposome following by degradation. Taken together, baicalein could be released selectively at the infected site to exert antibacterial capacity. HA/P/BAI-lip showed impressive antibacterial ability and dramatically decrease the bacterial burden of infection site and alleviate the infiltration of inflammatory cells, facilitating the recovery of infection.

Co-axial electrosprayed RAD001-loaded polycaprolactone/polyvinyl alcohol core–shell particles for treating pediatric brain tumours

Core-shell particles composed of polycaprolactone/polyvinyl alcohol (PCL/PVA) with pH sensitive properties were successfully fabricated by co-axial electrospraying in which PVA and PCL formed the shell and core layers respectively. The core–shell structure was confirmed by FTIR, DSC and SEM analysis. No chemical interaction between PVA and PCL core–shell were observed in the FTIR analysis. The RAD001 loaded core–shell particles showed a sustained and pH dependent drug release and was assayed via our previously developed HPLC method. After indirect treatment of the PF-A cells with the core–shell particles for 24 h and 5 days a decrease in cell viability was observed. Additionally, a comparison was made with our previously developed nanoparticles containing 2 %PVA-14 %SOL®-0.6 % RAD001, for the cell viability study on ependymoma. Our findings show that optimised core–shell particles exerted a significant effect for the 24 h and 5 day treatment however further studies are required to ensure toxicity of the control core–shell particles with no drug is reduced. In comparison, the 2 %PVA-14 %SOL®-0.6 %RAD001 uniaxial electrosprayed nanoparticles also exerted a toxicity effect decreasing cell viability with no toxicity observed for the control nanoparticles as well. Such pH-sensitive core–shell particles, which can degrade effectively in either acidic or neutral condition, have great potential for application in the biomedical field.

Biofilms from poly-vinyl alcohol/palmyra root sprout with Boswellia serrata, carbon dots and anthocyanin for sensing the freshness of sardine fish

One of the main issues that customers worldwide have is food adulteration. In commercial packages, freshness cannot always be determined visually. Here, we propose sensitive films for use in food packaging that could alter colour to indicate a change in freshness. Hybrid, multifunctional, and eco-friendly films were prepared from polyvinyl alcohol/palmyra root sprout (PVA/PRS), fused with soy protein isolate carbon dot (CD), Boswellia serrata (BS), and Clitoriaternatea anthocyanin (CTE). The films showed pH sensitivity, antioxidant, and UV barrier properties. By creating hydrogen bonds between PRS and the other fillers, adding these substances makes PVA less crystallized. These interactions were verified by infrared Fourier-transform analysis. When compared to PVA, PRS films had significantly lower moisture content and swelling ratios. The UV-blocking capabilities of the films were greatly improved by the addition of CD, BS, and CTE without compromising their mechanical, thermal, or water vapor barrier properties. The composite film PVA/PRS/CD/BS/CTE exhibited a maximum tensile strength value of 69.47 ± 1.49 MPa. The CT extract provides the film with superior antioxidant properties. The colorimetric films PVA/PRS/CTE and PVA/PRS/CD/BS/CTE showed distinct pH-responsive colour-change properties as well as good colour stability. The colorimetric films were used to test the freshness of sardine fish, and they revealed unique colour changes that indicated whether the fish sample was spoiled or not.

Preparation of pH-responsive fluorescent carbon dots under extreme alkaline conditions

Carbon dots (CDs) were prepared via a one-step solvothermal method using L-aspartate as the carbon source and ammonia as the solvent. The prepared CDs exhibited pH-sensitive properties and a color changing response to extreme alkaline pH ranges (12.0–14.0). O-related defect and N-related defect states induced by the protolated amino groups on the CD surfaces alternately dominated the fluorescence emission with a change in pH value, and the luminescence of different defect states was greatly affected by the excitation wavelength, which endowed the CDs with different pH-dependent fluorescence emission behavior under different light excitation. Based on the fluorescent emission behavior, which could be adjusted with a change in pH, the CDs showed potential application value as an instant inspection.

Readily Available Oral Prebiotic Protein Reactive Oxygen Species Nanoscavengers for Synergistic Therapy of Inflammation and Fibrosis in Inflammatory Bowel Disease.

A significant gap exists in the demand for safe and effective drugs for inflammatory bowel disease (IBD), and its associated intestinal fibrosis. As oxidative stress plays a central role in the pathogenesis of IBD, astaxanthin (AST), a good antioxidant with high safety, holds promise for treating IBD. However, the application of AST is restricted by its poor solubility and easy oxidation. Herein, different protein-based nanoparticles (NPs) are fabricated for AST loading to identify an oral nanovehicle with potential clinical applicability. Through systematic validation via molecular dynamics simulation and in vitro characterization of properties, whey protein isolate (WPI)-driven NPs using a simple preparation method without the need for cross-linking agents or emulsifiers were identified as the optimal carrier for oral AST delivery. Upon oral administration, the WPI-driven NPs, benefiting from the intrinsic pH sensitivity and mucoadhesive properties, effectively shielded AST from degradation by gastric juices and targeted release of AST at intestinal lesion sites. Additionally, the AST NPs displayed potent therapeutic efficacy in both dextran sulfate sodium (DSS)-induced acute colitis and chronic colitis-associated intestinal fibrosis by ameliorating inflammation, oxidative damage, and intestinal microecology. In conclusion, the AST WPI NPs hold a potential therapeutic value in treating inflammation and fibrosis in IBD.

Gelatin/agar pH-indicator film based on cranberry extract loaded with linalool nanoparticle: Survey on physical, antimicrobial, and antioxidant properties

In this study, linalool-nanoparticles (L-NPs) were prepared (encapsulation efficiency was 68.54 %) and introduced pH-indicator film based on cranberry-extract (CEF) to develop multifunctional smart films. XRD analysis and FTIR spectroscopy indicated that cranberry-extract (CE) and L-NPs were uniformly distributed in the gelatin/agar matrix and could change the intermolecular structure of the film. Color change of smart films showed that CE endowed the film with pH-sensitive property. As CE and L-NPs were added to the film, the water contact angle (WCA) was increased from 57.03° to 117.73°, the elongation at break (EAB) was increased from 12.30 % to 34.60 %. Additionally, the introduction of L-NPs enhanced the antioxidant activity (DPPH free radical scavenging rate increased from 26.80 % to 36.35 %) and antibacterial activity (against S. aureus and E. coli) of the smart film, which were verified by its retarding effect on pork spoilage.

Intelligent vegetable freshness monitoring system developed by integrating eco-friendly fluorescent sensor arrays with deep convolutional neural networks

Given the perishable and seasonal nature of vegetables, monitoring their freshness is essential to ensure food safety and reduce waste. Currently, there are limited packaging systems for fresh vegetables that incorporate intelligent freshness monitoring labels. Herein, we report on the development and application of a 3 × 6 fluorescent sensor array that exhibits pH-sensitive properties, utilizing curcumin, puerarin, and fisetin. During spoilage, yardlong beans and spinach, which had high protein content, produced alkaline volatile organic compounds (VOCs), whereas sweet corn, rich in sugar, emitted acidic VOCs. The fluorescent sensor array, integrated with deep convolutional neural network (DCNN), enabled non-destructive, real-time, and accurate classification of the freshness of the aforementioned three vegetables by detecting the acidity or alkalinity of their VOCs. The trained ResNet50 DCNN model achieved an overall accuracy of 96.21 % in classifying the freshness of the aforementioned vegetables in the testing set, with specific accuracies of 98.58 % for yardlong beans, 97.15 % for spinach, and 92.89 % for sweet corn, respectively. This intelligent freshness monitoring platform is adaptable for monitoring and classifying the freshness of a wide range of agricultural and food products.